How security admin rules and network security groups (NSGs) are evaluated Security admin rules and network security groups (NSGs) can be used to enforce network security policies in Azure. However, they have different scopes and priorities.# Security admin rules are intended to be used by network admins of a central governance team, thereby delegating NSG rules to individual application or service teams to further specify security as needed. Security admin rules have a higher priority than NSGs and are evaluated before NSG rules.
NSGs, on the other hand, are used to filter network traffic to and from individual subnets or network interfaces. They're intended to be used by individual application or service teams to further specify security as needed. NSGs have a lower priority than security admin rules and are evaluated after security admin rules.
Security admin rules are currently applied at the virtual network level, whereas network security groups can be associated at the subnet and NIC level.
This table shows these differences and similarities:

Reference:
https://learn.microsoft.com/en-us/azure/virtual-network-manager/concept-security-admins